Infusion set with safety device

ABSTRACT

An infusion set includes a base with a rigid piercing cannula or a soft catheter and rigid introducer needle. The infusion set also includes a line set with a fluid connector. The base and line set are configured such that the fluid connector can be used as a protector for the piercing cannula or the soft catheter, either before the device is attached to a user, or after the device is detached from the user, or both.

FIELD OF THE INVENTION

The present invention relates generally to infusion sets that use arigid infusion cannula or introducer having a sharp or piercing end thatpenetrates the skin of a patient. More particularly, the presentinvention relates to protecting the rigid infusion cannula or introducerattached to an infusion set before the cannula pierces the skin of auser, and/or after the rigid infusion cannula or introducer has beenremoved from the patient.

BACKGROUND OF THE INVENTION

Diabetes patients use some form of daily insulin therapy to maintainclose control of their glucose levels. Infusion pump therapy is onepreferred method. Infusion pump therapy occurs via an infusion cannula(i.e., an infusion needle or a flexible catheter) and requires aninfusion pump. Infusion pump therapy offers the advantages of continuousinfusion of insulin, precision dosing, and programmable deliveryschedules.

The use of an infusion pump requires the use of a disposable component,typically referred to as an infusion set, tubing set, which administersinsulin from a reservoir that is pumped into the skin of the user. Aninfusion set typically consists of a pump connector, a length of tubing,and a hub or base from which an infusion cannula extends. The base hasan adhesive that attaches the base on the skin surface during use. Thebase, with the infusion cannula attached thereon, may be applied to theskin manually or with the aid of a manual or automatic insertion device.

There are many available types of infusion sets incorporating varioustypes of infusion cannulas, including steel needle infusion sets andsoft catheter sets. Soft catheter sets can be inserted into a patientwith the aid of a steel introducer needle, which is later removed fromthe patient, leaving the soft catheter in place. The steel cannulainfusion set utilizes a steel needle or cannula that is secured to thebase.

An advantage of the steel cannula infusion sets is that the steelcannulas, due to their rigidity are less susceptible to kinking. Kinkingoccurs when the infusion cannula, be it rigid or soft, is unable toresist mechanical forces that may bend or twist the infusion cannula,resulting in a restricted flow of infusate exiting the catheter. Anotheradvantage of a steel cannula infusion set is that the steel cannulapierces the patient's skin without the need for a separate introducerneedle, as in soft catheter sets.

A steel cannula typically is protected by a disposable protective tube(typically made of plastic) that is attached to the base, surroundingthe steel cannula, prior to use, and such attachment generally is notvery secure. The user removes the disposable tube before the steelcannula is inserted into the user's skin. The protective tube isgenerally disposed of.

A steel cannula infusion set is illustrated in FIGS. 1-5

FIG. 1 illustrates a steel cannula infusion set 1 having a plastic fluidconnector or hub 22 that is detachably attached to a plastic base 10, afluid tubing set 28, and a plastic connector 26 which is attachable to apump (not shown). The connector 26 includes an outer wall 262. The lineset 20 includes the hub 22 and the fluid tubing set 28. The line set 20is attached to or detached from the base 10, as illustrated in FIGS. 2and 3.

FIG. 2 is a top view of the infusion set 1, illustrated with the hub 22attached to the base 10. An adhesive pad 19 is attached to the base 10and is configured to be attachable to the skin of the user. FIG. 3illustrates a view of the infusion set 1, wherein the line set 20 isdetached from the base 10. The base 10 includes an infusion adapter 14,to which the steel cannula 13 is attached.

FIG. 4 is a cross-sectional view of the infusion set 1, taken alonglines 4-4 of FIG. 1, that more clearly illustrates how the infusate(insulin) is pumped into the steel cannula 13. The hub 22 of the lineset 20 includes a hub port 25 that receives the fluid tubing set 28. Thehub 22 includes a flow cannula 24. The base 10 includes a main baseportion 12 and the adapter 14 includes a cylindrical lower portion 16,to which is attached the steel cannula 13, and a cylindrical inner wallportion 17 that is spaced apart from the lower portion 16. A pre-slitseptum 18 encloses an upper portion of the adapter 14, when the hub 22is not attached to the infusion base 10, as illustrated in FIGS. 3 and5.

When the hub 22 is attached to the base 10, the flow cannula 24penetrates the pre-slit septum 18 of the base 10 so that the steelcannula 13 is in fluid communication with the fluid tubing set 28, viachannel 11. This allows the insulin from the pump (not shown) to flowfrom the fluid tubing set 28 into the steel cannula 13 and the insulinexits the distal opening or tip 131 of the steel cannula 13 into thepatient.

FIG. 5 illustrates a cylindrical protector 30 attached to the base 10 toprotect the steel cannula 13. Prior to use, the protector 30, which isform-fit in the base 10, is removed, and the protector 30, typically atubular structure made of plastic, is disposed of.

A problem arises when a steel cannula infusion set is to be disposed.When the steel cannula 13 is removed from the user, which may be two orthree days after initial insertion, the user may no longer have thedisposable protector 30 or protective tube to cover the steel cannula 13that may now contain bodily fluids. Even if the disposable protectivetube 30 were available, since the attachment to the base 10 is not verysecure, the protective tube 30 could easily be detached from base 10 toexpose the used steel cannula 13.

A user is supposed to dispose of the steel cannula infusion set 1 in asharps container designed for disposal of items that include a sharpneedle, such as the infusion set 1 and syringes. However, a sharpscontainer may not be readily available when a user wishes to dispose ofand replace a used steel infusion set 1.

Accordingly, a need exists for an improved infusion set design andconstruction that can securely dispose of used steel needle infusionsets such that the steel cannula is not exposed, in order to protectpeople from such contact.

SUMMARY OF THE INVENTION

Objects of the present invention are to provide an infusion base tosecurely receive a protective element. In accordance with an aspect ofthe present invention, the protective element can be the connector ofthe fluid tubing set.

An objective of the present invention is to provide connecting elements,such as male threads and reciprocal female grooves, on the infusion baseand the connector of the fluid tubing set for engagement anddisengagement.

Another object of the present invention is to provide one or moreflexible tabs on the infusion base that can receive the connector andresist its detachment therefrom.

These and other objects are substantially achieved by modifying elementsof an infusion base to protect a steel cannula from unwanted contact.

BRIEF DESCRIPTION OF THE DRAWINGS

The various objects, advantages and novel features of the exemplaryembodiments of the present invention will be more readily appreciatedfrom the following detailed description when read in conjunction withthe appended drawings, in which:

FIG. 1 is a perspective view of a steel cannula infusion set;

FIG. 2 is a top view of the infusion set of FIG. 1;

FIG. 3 is a top view of the infusion set of FIG. 1 in which the line setis detached from the base;

FIG. 4 is a cross-sectional view taken along lines 4-4 of the infusionset of FIG. 1;

FIG. 5 is a cross-sectional view of the infusion set of FIG. 4, afterthe hub has been removed from the base;

FIG. 6 is a perspective view of an exemplary infusion set of the presentinvention;

FIG. 7 is a cross-sectional view of the base of the infusion set of FIG.6, after the hub has been removed from the base;

FIG. 8 is a cross-sectional view of the base of FIG. 7, illustrated withthe connector attached to the base;

FIG. 9 is a perspective view of an exemplary infusion set of the presentinvention;

FIG. 10 is a cross-sectional view of the base of the infusion set ofFIG. 9, after the hub has been removed from the base;

FIG. 11 is a cross-sectional view of the base of FIG. 10, illustratedwith the connector attached to the base;

FIG. 12 is a perspective view of another exemplary steel cannulainfusion set of the present invention;

FIG. 13 is cross-sectional view of the base of the infusion set of FIG.12, after the hub has been removed;

FIG. 14 is cross-sectional view of the base of FIG. 13, illustrated withthe connector securely attached to the base;

FIG. 15 is a perspective view of yet another exemplary steel cannulainfusion set of the present invention;

FIG. 15A illustrates a variation of the embodiment shown in FIG. 15;

FIG. 16 is a cross-sectional view of the base of the infusion set ofFIG. 15, after the hub has been detached from the base;

FIG. 17 is a cross-sectional view of the base of FIG. 16, illustratedwith the connector attached to the base;

FIG. 18 is a cross-sectional view of another exemplary embodiment of thepresent invention directed to a soft catheter infusion set;

FIG. 19 is a perspective view of another exemplary infusion set;

FIG. 20 is a cross-sectional view taken along lines 20-20 of theinfusion set of FIG. 19;

FIG. 21 is a perspective view of another exemplary infusion set; and

FIG. 22 is a cross-sectional view taken along lines 22-22 of theinfusion set of FIG. 19.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

FIGS. 6-8 illustrate one embodiment of an infusion set in accordancewith the present invention. In this embodiment, the infusion set 1 aincludes a line set 20 that is attachable to a base 10 a. The line set20 includes a hub 22 and a fluid tubing set 28 attached to the hub 22.An end of the fluid tubing set 28 is connected to a connector 26 a, suchas a conventional ISO 594 threaded connector sold under the trademarkLuer-Lok®, that can attach to an infusate reservoir or pump (not shown).In accordance with the present invention, the base 10 a includes anadapter 14 with a tapered or frusto-conical lower portion 16 a whosediameter decreases in the direction from top to bottom, and a threadedcylindrical inner wall portion 17 a. Space is formed between the lowerportion 16 a and the inner wall portion 17 a, sufficient to receive theconnector 26 a. The connector 26 a includes a tapered or frusto-conicalinner wall 260 a whose diameter decreases in the direction from top tobottom, and a cylindrical outer wall 262 a. The tapers (nominally 6%) ofthe lower portion 16 a and the frusto-conical inner wall 260 a arematching or complementary. Threads 263 are formed on the outer wall 262a of the connector 26 a (e.g., as in a Luer-Lok®) connector. Theconnector 26 a is configured to attach to the base 10 a. The threads 263on the outer wall 262 a of the connector 26 a are configured to berotatably attached onto corresponding threads or grooves 171 formed onthe cylindrical inner wall portion 17 a of the adapter 14, to detachablyattach the connector 26 a to the base 10 a, as illustrated in FIG. 8.

The outer threads 263 also function as a Luer-Lok® connector tointerface with corresponding grooves in the pump or reservoir (notshown) to administer the infusate to the user. FIG. 7 illustrates thebase 10 a with the hub 22 detached therefrom. The inner wall 17 a of theadapter 14 includes threads or grooves 171 for receiving the threads 263of the connector 26 a.

FIG. 8 illustrates the base 10 a with the connector 26 a secured on thebase 10 a. The connector 26 a is rotatably attached to be secured ontothe base 10 a. The threads 263 rotatably insert into the correspondingthreads or grooves 171, to securely attach the connector onto the base10 a. Reversing the rotation of the connector 26 a releases theconnector 26 a from the base 10 a. The manner in which the hub 22 issecured onto the base 10 a is similar to that illustrated in theembodiment of FIGS. 1-5. When the connector 23 is attached to the base10 a, as illustrated in FIG. 8, the cannula 13 is protected by theconnector 23, with the part of the cannula 13 that extends from thelower portion 16 a of the adapter 14 being housed in the space formedbetween the cylindrical inner wall 260 a of the connector 26 a, toprevent contact with the cannula 13, including its piercing tip 131.

In a modification of the embodiment of FIGS. 6-8, as illustrated inFIGS. 9-11, in the infusion set 1 b, the threads or grooves 171 and thethreads 263 (of the embodiment of FIGS. 6-8) can be deleted and theattachment between the fluid connector 26 b and the lower portion 16 bof the base 10 b can rely on the frictional interference between themating tapered or frusto-conical surfaces of the lower portion 16 b andinner wall 260 b, similar to a conventional ISO 594 Luer-type slipfitting.

FIGS. 12-14 illustrate another embodiment of an exemplary infusion setof the present invention. In this embodiment, an infusion set 1 cincludes a hub 22 attachable to a base 10 c. In this embodiment, thelower portion 16 c of the adapter 14 includes thread portions 161, andthe inner wall 260 c of the connector 26 c includes correspondingthreads or grooves 261 that receive the threads 161 when the connector26 c is rotatably attached to the base 10 c. In this embodiment, whichis not of the Luer type, the lower portion 16 c and the inner wall 260 cmay be cylindrical rather than frusto-conical.

FIG. 13 is a cross-sectional view of the base 10 c, illustrating thelower portion 16 c of the adapter 14 having threads 161 on its outersurface. There is space between the inner wall portion 16 c and theinner wall portion 17 c of the adapter 14 to receive the connector 26 c.In this space, the connector 26 c can be secured to the base 10 c. FIG.14 illustrates the base 10 c with the connector 26 c secured thereon. Inthis embodiment, the threads 161 of the lower portion 16 c of theadapter are rotatably attached onto the corresponding grooves 261 of theinner wall of the connector 26 c to attach the connector 26 c to thebase 10 c. Thus, the steel cannula 13 is securely protected fromunwanted external contact, in order to prevent unwanted or accidentalcontact with the tip 131 of the steel cannula 13 to avoid contamination.

FIGS. 15-17 illustrate yet another embodiment of the infusion set of thepresent invention. In this embodiment, the infusion set 1 d includes abase 10 d onto which is attached a line set 20. The line set 20 includesa hub 22 and a fluid tubing set 28, with a connector 26 d attached to anend portion thereof, as illustrated in FIG. 15. One or more flexibletabs 50 are attached to or formed integrally with a lower surface of thebase 10 d. The connector 26 d includes an annular rib 266 and acylindrical or frusto-conical inner wall 260 d, such that the annularrib 266 can fit into the space between the inner wall portion 17 d andthe lower portion 16 d of the adapter 14 d, as the flexible tabs 50deform to give way. When the flexible tabs 50 revert back to theiroriginal shapes, the flexible tabs 50 are able to retain the annularrib, as illustrated in FIG. 17, absent excessive pulling on theconnector 26 d. If the inner wall 260 d is cylindrical, the lowerportion 16 d is also cylindrical. Similarly, if the inner wall 260 d isfrusto-conical, the lower portion 16 d is also frusto-conical, to permita Luer-type friction fit when the inner wall 260 d engages the lowerportion 16 d, as illustrated in FIG. 17.

FIG. 15A illustrates a variation of the embodiment of FIG. 15. In thisembodiment, the base 10 d′ includes one or more substantially rigid tabs50′ attached to or formed integrally with a lower surface of the base 10d′. The connector 26 e of this embodiment includes one or more rigidtabs 266′, such as Luer-Lok® thread segments, such that when the tabs266′ of the connector 26 d are slotted into the spaces between the tabs50′ of the base 10 d′ and the connector 26 d is rotated slightly, thetabs 266′ and 50′ can be frictionally engaged to bind the connector 26 dto the base 10 d′, to provide a protective shield for the cannula 13.

FIG. 16 is a cross-sectional view of the infusion base 10 d of FIG. 15,and illustrates the flexible tabs 50 secured on the bottom surface ofthe main base portion 12 of the base 10 d. FIG. 17 illustrates theinfusion base 10 d with the connector 26 d secured thereon, after theouter lip 267 of the annular rib 266 of the connector 26 d has beeninserted into the space between the inner wall portion 17 d and thelower portion 16 d of the adapter 14. The tabs 50 provide resistance tothe outer lip 267 of the connector 26 d to detachably secure theconnector 26 d to the adapter 10 d, as illustrated in FIG. 17. It isconceivable that the one or more flexible tabs 50 can be formed on thelower portion 16 d to secure the connector 26 d to the base 10 d.

In embodiments of the present invention, the protector 30 (illustratedin FIG. 5) in the form of a cylindrical tube that is typically includedwith infusion sets can be eliminated altogether. The connectors 26 a, 26b, 26 c, 26 d and 26 e in FIGS. 6-17 can render unnecessary suchprotectors 30 because the connectors 26 a, 26 b, 26 c, 26 d and 26 e canbe used to shield the steel cannula both before and after the infusionset is used, thereby eliminating a part that can be made redundant andreducing the overall cost of manufacture. The elimination of the plasticprotectors 30 also eliminates the need to dispose of such protectors 30that would otherwise have to be recycled or placed in landfills.

The infusion sets 1 a, 1 b, 1 c, 1 d and 1 d′ can be provided to userswith respective connectors 26 a, 26 b, 26 c, 26 d and 26 e that areattached to the bases 10 a, 10 b, 10 c, 10 d and 10 d′, such that inorder to use the infusion sets, users first have to detach therespective connectors 26 a, 26 b, 26 c, 26 d and 26 e from the bases 10a, 10 b, 10 c, 10 d, 10 d′ to expose the cannulas 13 for attachment tothe users for infusion therapy. After the bases 10 a, 10 b, 10 c, 10 dand 10 d′ with the cannulas 13 pierce the user's skin, infusion therapycan occur, as described above, with regard to FIGS. 1-5. Thereafter,after the user removes the base 10 a, 10 b, 10 c, 10 d, 10 d′ from theuser's skin, and the connector 26 a, 26 b, 26 c, 26 d, 26 e is detachedfrom the pump or reservoir (not shown), the connector 26 a, 26 b, 26 c,26 d, 26 e can again be secured over the cannula 13 to protect thecannula 13, containing body fluids, from being contacted.

Thus, a component (protector 30) found in many infusion sets can beeliminated and the cannula 13 can be covered by a part (connector 26 a,26 b, 26 c, 26 d) that is already a part of the infusion set 1 a, 1 b, 1c, 1 d and 1 d′. This solves the problem of proper disposal of usedinfusion sets that would otherwise be disposed of with cannulas that areexposed. In this manner, the cannulas of infusion sets can be protectedbefore and after infusion therapy and used infusion sets can be securelytransported or disposed, with the cannulas secured thereon.

The embodiments described above relate to infusion sets that eachinclude a cannula 13, one that is rigid and typically made of stainlesssteel. However, the present invention is not restricted to such types ofinfusion sets. FIG. 18 illustrates a base 10 e of an infusion set 1 ethat utilizes a soft (e.g., Teflon®) catheter 30 a instead of a rigidcannula to deliver infusate to a user. As is known in the art, in a softcatheter infusion set, in order to attach the soft catheter 30 a intothe skin of a user, an introducer needle 31 is inserted through the softcatheter 30 a, as illustrated in FIG. 18, and the user pushes the needlehub 40 to which is attached the introducer needle 31 toward the user'sskin so that the needle 31 and the soft catheter 30 a both pierce theuser's skin. Thereafter, the needle hub 40 is removed from the base 10 eto remove the needle 31 from the user's skin while the soft catheter 30a remains in the user's skin. In accordance with the present invention,the infusion set can be configured such that the needle 31 and catheter30 a are both initially protected from exposure. Specifically, in theembodiment of FIG. 18, the needle hub 40 is initially placed on the base10 e, with the connector 26 b attached to the base 10 e protecting boththe soft catheter 30 a and the introducer needle 31. The manner ofattachment of the connector 26 b to the base 10 e can be the same asthat which is described for the cannula type infusion sets described inFIGS. 6-17. To permit infusion therapy, the needle 31 and needle hub 40are removed and the line set hub 20 is placed on the base 10 e, in thesame manner as illustrated in FIG. 4.

FIGS. 19 and 20 illustrate another soft catheter infusion set if, inwhich the fluid tubing set 28 is permanently connected to the adapter 14a of the base 10 f, such that when the needle hub 40 a is removed afterits needle 31 a has penetrated, via its tip 32, the user's skin,infusion therapy can occur as infusate is dispensed from the tubing set28, into the channel 11, and out through the catheter 30 b. Theself-sealing septum 18 a self-closes after the needle 31 a is removedfrom the catheter 30 b and out through the septum 18 a, as the needlehub 40 a is removed from the infusion set 10 a.

In the embodiment of FIGS. 19 and 20, the needle hub 40 a can be placedon the base 10 f, with the connector 26 b attached to the adapter 14 a,to protect both the soft catheter 30 b and the introducer needle 31 a.The manner of attachment of the connector 26 b to the base 10 f can bethe same as that which is described for the cannula type infusion setsdescribed in FIGS. 6-17.

The embodiment of FIGS. 21 and 22 is similar to that of the embodimentof FIGS. 19 and 20, except that this embodiment is directed to aninfusion set 1 g with a rigid or steel cannula 13 instead of a softcatheter. Since the rigid cannula 13 can penetrate the skin on its own,a separate introducer needle is not needed. The infusion set 1 gincludes a cannula 13 and a fluid tubing set 28 attached to the adapter14 b of the base 10 g, such that the fluid tubing set 28, channel 11 andthe cannula 13 are in fluid communication, to enable infusion therapy.Similar to the embodiments of FIGS. 6-17, in the embodiment of FIGS. 20and 21, the manner of attachment of the connector 26 b to the base 10 gcan be the same as that which is described for the cannula type infusionsets described in FIGS. 6-17.

Although only a limited number of embodiments of the present inventionhave been described in detail above, those skilled in the art willreadily appreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe appended claims and their equivalents.

What is claimed is:
 1. An infusion set comprising: an infusion base forattachment to a user, the infusion base including threads; an infusioncannula extending from the infusion base, the infusion cannulacomprising a piercing part at an open end for piercing the user's skin;a hub connectable to the infusion base; a tube set comprising one endattached to the hub and an open end, the open end of the tube setcomprising a connector including threads, the connector (1) beingattached to the threads of the infusion base to protect the piercingpart of the infusion cannula when infusate is not being dispensed, and(2) being removable from the threads of the infusion base and attachableto an infusion pump for dispensing infusate.
 2. The infusion set asclaimed in claim 1, wherein a flow path connecting the infusion cannula,hub and tube set is formed when the hub is connected to the infusionbase.
 3. The infusion set as claimed in claim 2, wherein the basecomprises an adapter having a lower portion, an inner wall portion and agap between the lower portion and the inner wall portion, the gapconfigured to receive the connector.
 4. The infusion set as claimed inclaim 3, wherein the outer wall comprises an inner wall, space formed bythe inner wall, the space for receiving the infusion cannula when theconnector is secured in the gap between the lower portion and the innerwall portion.
 5. The infusion set as claimed in claim 4, wherein theouter surface of the connector comprises the threads and the inner wallportion comprises the corresponding threads for receiving the threads ofthe connector when the connector is rotatably attached to the base, withthe infusion cannula housed in the space formed by the inner wall of theconnector.
 6. The infusion set as claimed in claim 4, wherein the lowerportion of the adapter comprises the threads and the inner wall of theconnector comprises the corresponding threads for receiving the threadsof the lower portion when the connector is rotatably attached to thebase, with the infusion cannula housed in the space formed by the innerwall of the connector.
 7. The infusion set as claimed in claim 2,wherein the infusion pump pumps infusate from an infusion reservoir intothe flow path to dispense infusate to the user.
 8. The infusion set asclaimed in claim 1, wherein the infusion cannula is rigid.
 9. Theinfusion set as claimed in claim 8, wherein the infusion cannula is madeof stainless steel.
 10. The infusion set as claimed in claim 1, whereinthe infusion cannula is non-rigid.
 11. The infusion set as claimed inclaim 10, wherein the infusion cannula is made of a resilient plasticmaterial.
 12. The infusion set as claimed in claim 1, wherein theconnector is configured to form a leak-free connection with the infusionpump.
 13. The infusion set as claimed in claim 1, wherein the connectoris configured for covering the piercing part of the infusion cannula.14. A method for using an infusion set having an infusion cannula and afluid connector, comprising: inserting the infusion cannula into a skinof a user, the infusion cannula extending from a base and comprising apiercing part at an open end of the infusion cannula, a hub beingconnectable to the base and attached to a first end of a tube set, thetube set including a second end comprising the fluid connector;connecting the fluid connector to an infusion pump for dispensinginfusate, the fluid connector and the base both including threads;applying infusion therapy through the infusion cannula; removing theinfusion cannula from the user; disconnecting the fluid connector fromthe infusion pump; and attaching the threads of the fluid connector tothe threads of the base to cover the infusion cannula to preventexternal contact with the infusion cannula.
 15. A method for using aninfusion set having a base, an infusion cannula and a fluid connector,comprising: securing threads of the fluid connector to threads of thebase to cover the infusion cannula to prevent external contact with theinfusion cannula, the infusion cannula extending from the base andcomprising a piercing part at an open end of the infusion cannula, a hubbeing connectable to the base and attached to a first end of a tube set,the tube set including a second end comprising the fluid connector;detaching the fluid connector from the base prior to infusion therapy;inserting the infusion cannula into a skin of a user; connecting thefluid connector to an infusion pump; and applying infusion therapythrough the infusion cannula.